Density of forests in Great Nicobar may be far higher than estimated, flag ecologists
The government has planned four projects in the region — International Container Transshipment Terminal, Greenfield International Airport, Gas and Solar based Power Plant and Township & Area Development Projects.
Since August, one question has puzzled several ecologists across the country: How dense is a rainforest?
The question emerged when the Andaman and Nicobar Islands Integrated Development Corporation Limited (ANIIDCO) began the process for selection of contractors for “enumeration, felling, logging, and transportation” of trees as part of the Great Nicobar development project.
According to existing research, a rainforest can have trees ranging between 500 and 800 per hectare of land, an ecologist said.
“It is anywhere in the range of 500 to 800 trees per ha of land, of at least 30cm girth size or larger. Rainforests are so dense that at times it’s difficult to see the open sky through the canopy,” the ecologist said requesting anonymity. But, he added, to get a true sense of how dense it can be a “meticulous tree enumeration” should be taken up in Great Nicobar’s forest.
The mix of big and small trees can go up to 1,000 trees a hectare, said NH Ravindranath, retired professor, Indian Institute of Science, and a forestry expert.
“Tropical evergreen forests or rainforests are the densest forests with multiple layers. They have extremely high plant biodiversity… In India the high monsoon regions such as Western Ghats, and Andaman and Nicobar region have these forests and tree density in some of these areas can be as high as 1000 trees per ha because they are a mix of big and small trees,” said Ravindranath, whose focus has been the Western Ghats region.
But it’s not the trees alone.
“You will not find large mammals like lion, tiger or leopards here, but the ecosystem is extremely rich,” he said.
If diverted, as is envisaged under the development project, an inter-linked ecosystem of lichens, orchids, ferns, lianas and moss is likely to be lost, the ecologist cited in the first instance said.
The government has planned four projects in the region — International Container Transshipment Terminal (ICTT), Greenfield International Airport, Gas and Solar based Power Plant and Township & Area Development Projects — for which an area of 166.10 sq.km is required. Of this, forest area is about 130.75 sq.km.
Of the forest area under the project, tree felling is envisaged in 64.76 sq km according to ANIIDCO’s call for EOI for tree enumeration and felling. In Phase 1 (between 2025 and 2035), an area of 10.45 sqkm will be targeted.
But the complexity of the nature of these forests has experts concerned.
“These forests are at threat from infrastructure and climate change. There are projections that show that many of these will become deciduous forests with rise in average temperatures which is why they need utmost care. Once these forests are lost they cannot be recreated because of their complex ecosystems,” Ravindranath said.
According to an estimate by independent experts, based on published research on rainforest density, around 500,000 trees will be felled in phase 1 itself.
“That would mean, by a conservative estimate, around 5 lakh trees are likely to be felled in phase 1 and around 32 lakh trees when total area for felling is considered,” the ecologist cited in the first instance said.
These estimates, however, are far higher than those of the Centre.
According to minister of state Kirti Vardhan Singh’s response in Lok Sabha in July, the estimated number of trees to be affected is 964,000 — for the entire project.
“The Central Government vide letter dated 27.10.2022 has accorded the In Principle/Stage-1 approval for diversion of 130.75 Sq. km forest land for sustainable development in Great Nicobar Island… The estimated number of trees to be affected is 9.64 lakhs. However, more than 50% i.e. 65.99 Sq. km of the area proposed for diversion is reserved for green development where no tree felling is envisaged. It is expected that about 15% of development area would continue to remain as green and open spaces and therefore the number of trees likely to be affected is going to be less than 9.64 lakhs,” Singh said in response to a question by MP Asaduddin Owaisi.
Owaisi had raised concern about the high number of trees likely to be cut and displacement of the indigenous population for the project that the government has attributed “significant strategic and national importance” to.
The disparity in the number of trees likely to be axed is also why scientists are waiting for ANIIDCO’s enumeration exercise.
“We will be carrying out enumeration only to begin with. Enumeration is not tree felling,” an ANIIDCO official had said on September 28.
“It’s important that the enumeration is done scientifically by counting trees plot wise. That data must be shared. The density of trees in the rain forests of south and southeast Asia is similar and hence GNI cannot be an outlier,” said another ecologist.
In April 2003, a paper, published in the International Journal of Primatology, that surveyed the distribution and status of the long-tailed macaque in the Nicobar Islands, found tree density to be highest on Great Nicobar (996.9/ha) followed by Little Nicobar (910.3/ha) and Katchal (825.5/ha). It said that the canopy is also denser (92.8%) on Great Nicobar versus Little Nicobar (90.1%) and Katchal (87.3%).
The paper noted that rain forest species are highly susceptible to habitat disturbance and loss due to their low rate of production and dispersal and a high degree of specialization. “Increasing human activity in the form of agriculture, commercial development and tourism in insular rain forests causes severe threats to the endemic flora and fauna,” it said.
In 2015, another paper, “Diversity, distribution and vegetative structure of mangroves of the Andaman and Nicobar Islands, India”, published in Springer, found that Andaman and Nicobar Islands consist of 38 mangrove species. Scientists pegged the average tree density in ANI at 1746 trees per hectare and varied from 487 to 2383 per hectare.
In a 2008 paper published in Taiwania, scientists from Pondicherry University investigated tree diversity in “giant evergreen forest” of Andaman and Nicobar Islands.
A one-hectare square plot was established in sites Kalapahad (KP) and Macarthy Valley (MV) of Middle Andamans, in which all trees ≥ 30 cm girth at breast height (gbh) were enumerated. Tree diversity totaled 105 species and there were 1311 individuals of trees (579 in one of the 1 ha plots and 732 in another).
The Nicobar Islands fall Sundaland Biodiversity Hotspot and cover the western half of the Indonesian archipelago — a group of some 17,000 islands stretching 5,000 kilometers — and is dominated by the islands of Borneo and Sumatra.
Some scientists also pointed out that the quantification of impact on trees has to be understood by loss of other unique plant and animal species. “Tropical rain forests are very high in diversity. They have orchids, ferns, epiphytes apart from birds, amphibians, primates depending completely on them. For the Shompen, a particularly vulnerable tribal group, these rain forests are foraging ground mainly for food. They take pandan fruits from here apart from other foods that are an integral part of their diet,” the first rainforest ecologist added.
The Forest Survey of India defines “very dense forest” as all lands with tree canopy density of 70% and above. FSI’s state of forest reports depend on satellite data for their assessment. In Nicobars, total geographical area is 1841 sqkm of which 1148.10 sqkm is very dense forest, according to FSI.
HT had reported on November 22, 2022 that the loss of forests in Great Nicobar Island on the Bay of Bengal will be compensated by afforestation in Haryana’s Aravallis, officials of the environment ministry have said. The Aravallis is over 2,400 km away in a different ecological zone (tropical dry forests) from Great Nicobar (tropical evergreen forests), but rules allow for such remote compensatory afforestation.
One of the ecologists said that most of the forested areas are planned for eco-tourism and recreational areas. “I would argue that forest area needed for strategic and defence needs is likely to be much smaller than what the mega project requires. Strategic needs can and should therefore be met with much less environmental harm,” he said.
In recent months, there has been a debate between Congress leader and MP Jairam Ramesh, and Union environment minister Bhupender Yadav over the ecological impacts that the mega infrastructure project is likely to have flora and fauna and tribal populations including the Great Nicobarese and the Shompen. Yadav has defended the project, emphasising that “exemplary mitigation measures” have been incorporated to minimise environmental impact, “keeping the strategic, national and defence interests” in mind.